Airplane launching apparatus



May 6, 1941- I w. E. wlLsoN 2,240,947

AIRPLANE LAUNCHINC- APPARATUS Filed June 21, 1939 nventor J //@KZMU Mm 7% trge/gd Patented May 6, 1941 UNITED. siln'ras ATEN'i-- orificeamsn v A Amrum: musculus Armaarus Wallace E. Pa. l Appucauun June 21, 19st. senil N6. 280,266

A1'1 mami. (ci. 244-83), My invention relates to an apparatus for facili- I tating the launching of airplanes, and the primary object and advantage of the invention is to provide an apparatus of the character described, which will operate inV conjunction with the airplane mechanism to accelerate the take in its use, automatically and conveniently controllable, positive in its action, and ycomparatively economical in its manufacture, installation, operation and maintenance.

With the foregoing and other objects in view which will appear as the description proceeds, the 'inventionresldes in the novel construction, combination and arrangement of parts herein specifically described and illustrated in the accompanying drawing, but it is to be understood, that the latter is merely illustrative of an embodiment of the invention, and that the actual needs of practice and manufacture may require certain mechanical variations from the embodiment shown. It is, therefore, not intended to limit the invention to the disclosure thereof herein illustrated, but rather to denne such limitations to the scope of the claim hereunto appended. y

In the drawing wherein like numerals of reference designate corresponding parts throughout the several views:

-Figure 1 is a side elevational view, partly in section, of an airplane launching apparatus constructed in accordance with the invention.

Figure 2 is a transverse cross sectional view 'a power mechanism involved in the present invention.

f Figure 6 is a view on line 6 6, Figure 5.

Referring in detail Ito the drawing I denotes a straight channel of any required length, and preferably constructed of concrete. The channel is comparatively shallowand substantially rectangular in transverse cross section,` and is provided with a top 2 having a narrowvslot 3, which latter opens into the channel. The slot is disposed atthe center of the top and extends throughout the length of the latter. The channel preferably has a sloped bottom 4 to direct any water that might enter the channel into suitable disposed drainfholes 5 formed in said bottom. The .top may be provided with elevated ridges 8 which are disposed along respective sides of .the top opening of the slot to minimize the entrance of water or other extraneous matter into the channel. The channel is constructed in the runway of. the airplane neld, and the surface of the top 2 is actually a part ofthe surface of said eld runway.

, A track structure, comprising a pair of track rails 1, is suitably fixed in the channel I.. The rails extend parallel to each other, and are secured against respective side walls of said channel.

The track rails l are substantially V-shaped in transverse cross section, with the apexes thereof being disposed toward each other. The track rails extend throughout the length of the channel I, and are horizontally opposed to each other.

A brake rail 8 is fixed at the center of `:the channel bottom 4, and extends longitudinally throughout the length of the latter. The brake rail may be insulated from the channel structure by any suitable insulation 8' for the purposehereinafter to be described. i

A carriage 8 is mounted in the channel I, and is supportedon the track rails l. Each side of the carriage is provided with a longitudinally extending track groove Ill, which latter is substantially V-shaped in transverse cross section. A ball race II is secured in each wall of each'of said track grooves, whereby both the upper and the lower surfaces of each of the track rails is engaged by a ball race II.

It will be evident that any other suitable type oi' track structure and carriage may be employed without departing from the spirit of the invention. However, it is sential that the carriage be constructed and mounted to allow same to travel freely, inY either direction with a minimum of friction, both-when the carriage is depressed upon the track rails by its own weight,

`or when said carriage'` is elevated against the track rails by a pulling or lifting action exerted Y toI said carriage in the operation of lthe ap-` paratus in the manner to he described.

A brake bar l2, including a replaceable brake shoe I3, is mounted inthe bottom of the carriage l and extends longitudinally in the latter; The brake shoe is of considerable length and width, and together with the brake bar, is pro- 2,240,947 f A automatically operable for release to allow the 30, with conductors 32 to a suitable, automati- Jectible in the carriage to dispose said brake'y shoe below the plane of thelower face of the carriage bottom to frictionally engage the top of automatically suspend the operation of the mothe brake rail 8 whenV it is desired to retard the travel of the carriage during the operation of the apparatus. v

A connecting rod Il extends through an opening Il inthe top of the carriage l, and has its lower end secured inthe brake bar l2. The connecting rod inclines rearwardly at an angle from the vertical, and the upper end thereof projects through the slot 3 at the top of ythe channel I, and carries a connecting eye Il having a swivelled attachment therewith.

A spiral spring l1 is mounted in the carriage l on the connecting rod I4. One end of the spring abuts against thetop ofthe carriage, and the other end thereof abuts against the brake shoel2, as clearly illustrated in Figure 2. The

spring normally functions to force the brake shoe Il against the brake rail l to effect the braking operation, while a pull on the connecting rod will elevate the brake bar and brake shoe, against the action of the spring, to clear said brake rail.

The airplane I8 to be launched is positioned at one end of the channeled runway, 'directly' over the channel I and in alignment with the latter. The airplane is provided with an attaching mechanism I9, which includes a rearwardly curved connecting' arm 20 projecting and depending from the airplane body. The attaching mechanism extends into the airplane body, and is maintained in position by a suitable ratchet mechanism 2|. An adjusting wheel 22 is xed to the upper end of the attaching mechanism, whereby the position of the associated connecting arm may be varied to meet conditions found in practice. A slip ball 23, having a curved passage 2l, is mounted on the curved connecting arm of the attaching mechanism, and is loosely shiftable on said connecting arm.

A hitching cable 25 has a swivelled connection with the slip ball 23 and with the swivelled eye I0 on the connecting rod I4. The hitching cable is comparatively short, so when the carriage 9 is joined with the airplane i8 by the hitching cable, the latter will extend on an eifective pulling angle, as shown in Figure l. 'Ihe attaching mechanism I9 is preferably disposed slightly forward of the center of gravity of th'e airplane, so that the pulling action of the hitching cable will not tend to overbalance the airplane on its landing gearing.

A towing cable 26, having a swivelled connection 2`| with the front end of the carriage 9, extends in the channel I, passes over a suitably supported sheave 28, and winds on Ia spool or drum 29. The drum and said sheave are located and suitably housed at the end of the channel remote from the starting end of the latter.

The drum 29 is operated by any suitable type of power device, preferably by an electric motor I0, which is joined with said drum by a suitable coupling clutch 3|. The latter may be of lthe known roller type, as shown in Figure 6, which operates automatically to rotate the drum in the pulling or towing direction only, and which is vcally controlled switch element Il, the latter will function to open the operating circuit to tor whenever the brake shoe Il is in contact with the brake rail, whereby the yoperation of the drum 29 and the towing. pull on the towing cable are likewise discontinued. It is apparent that any other system of operating control may be successfully employed without departing from the spirit or sacrificing any advantages of the invention.` Such systems may necessitate the presence of the attendant \at location, or may be operable from points remote from -the latter. In launching an airplane with the use of my improved apparatus, the former is positioned at the starting end of the channeled runway. and the hitching cable 25 is connected with the airplane by placing the slip ball 28 on the curved connecting arm 20 of the attaching mechanism II. The airplane motors are operated with sufiicient speed to propel the airplane under its own power in the usual -manner when taxying along the flying field for a take off. As soon as the airplane begins to travel under its own power, the motor lo is started to operate the drum. 2i and lthereby wind the cable 2l on the latter to effect the towing operation.

- When the hitching cable 25 is ilrst drawn taut by its pulling action, the brake shoe Il will disengage the braike rail I, and the carriage I is free to travel on the rails 1, and the towing operation will be in effect. So long as the speed of the towing action is greater than the speed of the airplane under its own power, the towing action will accelerate the take of! speed of the airplane. However, when the speed of the airplane under its own power exceeds the speed of the towing action, the hitching cable 2l will become slack, and the spring ll will function to force the brake shoe I2 into frictional engagement with the brake rail. Such braking action will cause the control of the switch Il to discontinue the operation of the motor lll and suspend the towing operation, and the forward movement of the carriage will be immediately retarded and stopped within a very short distance. As the accelerated airplane passes over the retarded carriage the hitching cable 25 will automatically draw the slip ball 2l from the connection arm 20 to fully release the airplane from its connection with the launching apparatus.

' 'Ihe attaching mechanism I l is adjustable, in the manner set forth, so that, in cases of emergency, the pilot within the airplane is enabled to shift the connecting arm 20 to a position to allow and cause the release of the slip ball 23 therefrom during the towing operation, even when the speed of the towing operation exceeds the speed of the airplane under its own propulsion, and power.

After each towing operation, the carriage i is returned to the starting end of the channel I, by any suitable device or in any suitable manner. The return travel of the carriage draws back the towing cable 26 as it unwinds from the drum 29. Due to the construction and operation of .the coupling clutch 3l, as stated, the drum always may be freely rotated in the reverse direction.

It is of course evident that, instead of employing-the preferred flexible bitching cable 25 and attaching mechanism I9 for joining the carriage 9 with the airplane, any other type of hitching mechanism may be successfully used that is capable of automatically releasing the airplane after the latter is travelling underits own power A tion diiering from any of the others, so that a runway best located for airplane launching, generally into the wind, may be selectively employed for launching the airplane.

The present inventionprovides a most eniclent apparatus of its kind, which will effec-U tively operate, in conjunction with the embodied propulsion mechanism of an airplane, for quickly accelerating the speed of the latter to produce the momentum necessary to cause the airplane to leave the ground within a comparatively short distance of travel, whereby the areas of airplane fields may obviously be greatly reduced, which embodies relatively iew parts, and which may be conveniently, safely, and economically employed inrge manner and for the purpo se herein set' fo what I claim is; In an airplane launching apparatus ofthe character described, the combination ci a chan--y nel provided with a top, said top having a narrow slot extending throughout the lengththereof, a pair of elevated ridges disposed on said top at' respective sides of said slot, a pair of parallel extending track rails carried by respective side walls of said channel, a carriage mounted in said channel and including revoluble means engaging said track rails for shiftably supporting said carriage on -the latter, said channel having a sloped bottom, a brake rail iixed in said channel bottom, a brake bar mounted in the bottom of said carriage and being projectible' below the latter to engage said brake rail, a connecting rod inclining rearwardly from the vertical shiftably extended through said carriage and having its lower end fixed in said bar, said rod 'projecting through said slotand carrying a swivelled eye at the upper end thereof, a spring mounted on said rod and normally functioning to -force said bar against said brake rail, a bitching device connecting with said eye and with the airplane, and a power mechanism for actuating said carriage to accelerate the momentum of the airplane while the latter is travelling under its own power,

the movement of said carriage when exerting a pull on said device disengaging said bar from said brake rail, said device embodying means for automatically eiecting the release of the airplane therefrom when the speed of the latter exceeds the travelling movement of said carriage.

WALLACE E. WILSON. 

